If you don't want to use chemicals, use water pressure. Set yur hose nozzle to flat and, while supporting your plant with one hand, hose those suckers off. Don't use the JET setting and don't have the water pressure on so high that it feels like Jet setting. Aphids are soft bodied so the water pressure will kill them & it won't matter that the aphids end up in the dirt. Once you get rid of the aphids, the ants will depart as they are eating what the aphids were depositing. You will need to keep an eye on the plants to make sure the aphids don't return.